Magnetic holder for telephone hand set



Sept. 19, 1961 w. G. HOKETT 3,001,032

MAGNETIC HOLDER FOR TELEPHONE HAND SET Filed Nov. 9, 1959 INVENTOR.

- um $7M United States Patent C 3,001,032 MAGNETIC HOLDER FOR TELEPHONE HAND SET William G. Hokett, 2322 N. 9th St., Phoenix, Ariz. Filed Nov. 9, 1959, Ser. No. 851,837 6 Claims. (Cl. 179-147) This invention relates generally to improvements in telephone instruments and more particularly is concerned with a magnetic device for holding the hand set on the base.

It is well known that a hand set which consists of a handle part with a transmitter on one end and a receiver on the other, and which is held in a cradle on the base of the telephone, often becomes dislodged from the cradle due to careless handling, accidents, or vibration. When the hand set becomes dislodged from the cradle the telephone bell cannot be rung.

Heretofore some attempts have been made to provide magnetic devices to hold the hand set in place in the cradle by magnetism, thereby making it more difficult for the hand set to become dislodged from its proper position. All of these devices, however, so far as this applicant can determine, are dependent upon permanent magnets for their operation. It is well known that permanent magnets can be made that will hold very strongly ii metal to metal contact is made between opposite poles. However, once this contact is broken then the attraction between the opposite poles decreases inverse of the square of the distance between the opposite poles. Therefore, the magnetic pull exists in a necessary amount only when the poles of the holding magnet are either in contact or very close to contact with an armature or an oppositely polarized holding magnet.

Furthermore, the holding of the magnets, when there is metallic contact between opposite poles, may be so great that it will be inconvenient for sick persons or those not having strong wrists and arms to remove the hand set from the base in order to operate the telephone.

In view of this I have made an electro-magnetic hand set holding device for the particular type of telephone having a base with a switching dial and a cradle for holding the hand set in the cradle of the base when the instrument is not in use. This type of telephone has switches operated by plungers in the cradle to switch the ringing circuit to the talking circuit when the hand set is removed from the cradle and, conversely, to switch the talking circuit to the ringing circuit when the hand set is resting in the cradle. This type of telephone instrument was previously called a French telephone.

My improvement for this type of telephone provides an electro-magnetic means for holding the hand set in the cradle when it is placed there after use, together with Patented Sept. 19, 1961 ICC Other objects will appear hereinafter.

I attain the foregoing objects by means of the devices, parts and combinations of parts shown in the accompanying drawings wherein-,-

FIGURE 1 is a plan view of a telephone set of the type herein concerned with my improvements installed thereon;

FIGURE 2 is a side elevational view of the hand set, and a portion of thebase, and cradle, together with a semi-diagrammatic wiring circ t; said cradle being shown in vertical midsection substantially on line 2-2, FIGURE 1; and

FIGURE 3 s a fragment of the top of: the base, shown substantially on line 33 of FIGURE 1, and showing the magnet cutoff switch, in mid-section.

Similar numerals refer to similar parts in views.

In the drawing 2 indicates the base of a French type telephone instrument; 3 indicates generally the hand set which includes a transmitter 4 and a receiver 5. These last mentioned parts are held together by a handle 6 to the several make the complete hand set instrument.

an easily operated disconnecting switch for said electromagnet.

' Another object of the invention is to provide a warning light which will light when the hand set is removed from the cradle. This is intended to warn the user, or anyone observing the telephone, that the hand set is oil the cradle and, therefore, the ringing circuit is disconnected.

Another object is to provide a means for disconnecting the electro-magnctic circuit of the holding magnet when desired; this means including a mechanism which can be operated by a natural and easy movement of the user when the hand set is grasped and picked up for use.

Still another object is to provide switching means for lighting the warning lamp when the hand set is removed from the cradle and maintaining position until the hand set is replaced in the cradle.

Still another object is to provide means for maintaining the electro-magnet activating circuit open so long as the hand set is removed from the cradle.

the lamp in a lighted 0 transformer 37. The leads 38 of Ordinarily when not in use the hand set rests in a cradle 8 in base 2. Within the cradle there may be plunger-s or other apparatus necessary for switching the telephone ringing circuit which is operative when the hand set is in position in the cradle, as shown in FIG- URE 2, to the talking circuit, when the hand set is removed from the cradle. These circuits and the switching mechanism by which they operate are not concerned herein and not shown.

The cradle includes two supports 9 and 10 which are notched at the top to receive and hold the handle 6 of the hand set when not in use.

As shown in FIGURE 2 the handle portion 6 of the hand set is resting in the cradle 8 and two plunger switches 12 and 14 are depressed by the weight of the hand set. In telephones of this type heretofore made the hand set rested in the cradle and was held by gravity only. It was, therefore, easy to dislodge the hand set by any sudden motion of the base 2 of the telephone, and the user often forgot to replace the hand set on the cradle. In this case the telephone connecting system could not ring the bells of the ringing circuit because the connections remained on the talking circuit.

According to my invention I provide an electro-magnet 15 which is placed in the central portion of the handle 6 with its poles disposed longitudinally and with their ends protruding somewhat so as to contact, or almost contact, an armature 16 on base 2 when the hand set is in the position shown and the telephone is not being used. In order to activate magnet 15 I provide circuit wiring including contacts 16 and 16a at two longitudinally separatedpositions on the inner face 6a of the handle. These contacts are disk shaped metallic buttons. In mating relation with these contact buttons I provide a second pair of contacts 18 and 18a which are disposed in the top of plungers 22 and 22a which are located in the bottoms 20 of the notches 21a in supports 9 and 10. These plungers are normally held in raised position by springs 24 and 244.

There are contacts 27 on the upper face of flanges 28 on the lower ends of plungers 22 and 22a which are in contact with conductive rings 30 embedded in the material 31of the base 2 adjacent the plungers. Contact 30 is connected to an indicator warning lamp 33. The other terminal of lamp 33 is connected to a wire 34 which leads to a rect'fier 35. Rectifier 35 is connected in circuit with primary 36 with a step down the primary of this transformer are thence connected to a convenient source of electric power'such as a volt lighting circuit.

The opposite terminal 40 of the secondary of the transformer 37 is connected through wire 41 to a central conductor rod 42 in plunger 12. Current from this Wire is connected thorugh buttons 18 and 16a to the winding 43 of magnet 15 and thence through contact buttons 16a and 18a to a conductor wire 44 which, in turn, is connected to a magnet disconnecting switch 45 which is built into the body of the material 31 of the base.

This switch has an upwardly protruding contact plate 46 which is normally held upward by springs 47 and slidably retained in a recess 48 in the material 31 at the top of body 2. It is to be noted that the contact plate 46 protrudes upwardly from body 2 between the supports 9 and and is disposed so as to extend along one side of the handle portion 6. It may, therefore, be easily reached and depressed by the thumb of a person picking up the hand set. It may be otherwise easily reached, if desired, by the fingers of the users other hand. When the plate 46 is depressed the circuit from wire 44 through the contact points 50' and wire 51 is broken. Since the current from the rectifier flows from wire 51 to wire 34 the current energizing magnet is discontinued. This structure makes it possible to demagnetize the hold-down magnet 15 to permit the hand set to be removed from the cradle by one hand of the user.

A further consideration of the wiring shows that when the hand set is removed from the cradle the contacts 27 and 30 are closed and, therefore, the circuit from wire 41 through the connector 41a to contact 29 and thence to contact 31 and through the signal lamp wire Slia to lamp 33 and thence through wire 34a to wire 34 is completed and the lamp, lights and remains lit so long as the hand set is removed from the cradle.

From the foregoing it appears that so long as the hand set is in place on the base the hand set is firmly kept in position by magnet 15 acting on armature 16.

When the hand set is to be removed the magnet 15 may be die-energized by pressing downward on the plate 46 of switch 45.

The hand set may then be removed from the cradle and, when this is done, the lamp 33 indicates that it is off the cradle. Anyone observing the lamp burning knows that the hand set is out of place and should be replaced to restore the to ephone to the ringing circuit.

I claim:

1. In a telephone instrument having a base, including a ringing circuit and a talking circuit and a cradle and a hand set adapted to be supported in said cradle and connected electrically to said base, a magnet energizing circuit including an electro-magnet in the handle portion of said hand set, an armature for said magnet in the top of said base and disposed in magnetic relation to said magnet in said hand set when the hand set is in the cradle of said base, means including wiring connected to an outside source of electricity for energizing said electromagnet when resting in said cradle, a switch on said base adjacent to said cradle for disconnecting the magnetic means energizing said magnet, a signal light on said base connected to an outside source of power and a switch operated by the weight of said hand set when in said cradle energizing said signal lamp and disconnecting said magnet energizing circuit when the hand set is removed from said cradle.

2. The device as described in claim 1 wherein there are vertically slidable plungers operable in the base of said cradle, springs normally holding said plungers upward to open circuit position, and contact members on said plunger to connect the magnet in said hand set with said source of power when the hand set is placed on said plungers and to disconnect the magnet from said source of power when the hand set is removed from said plungers and from said cradle.

3. In a telephone instrument having a base provided with a cradle on its upper side, including two spaced apart notched supports, a hand set including a transmitter and a receiver disposed on the end portions of an elongated handle adapted to rest in the notches of said supports in said base, plunger switches slidably operating vertically in the bottoms of said cradle notches, springs in said base normally holding said plunger switches resiliently in raised position; apparatus for magnetically holding said hand set in said cradle including an electro magnet disposed in the handle of said hand set with its pole ends separated longitudinally along said handle, extending outward from the under face of said handle when the hand set is resting in said cradle, an armature magnetically cooperative with said electro magnet pole pieces disposed on the top of said base between said notched supports, electrical circuits including wire conductors and a source of electricity for energizing said electro magnet when said hand set is resting in said cradle whereby said hand set is held in said cradleby electro magnetic attraction for said armature on said base, a switch on said base adjacent to said armature adapted to be operated by the digits of the hand of a person picking up said hand set and connected through said electrical circuits to said magnet energizing source of electricity so as to open the circuit energizing said magnet when operated, and an electrical signal lamp on said base connected to said source of electricity through switching means in at least one plunger in said base to indicate when said hand set is removed from said cradle.

4. In a telephone instrument having a base provided with a cradle on its upper side, including two spaced apart notched supports, a hand set including an elongated handle, a transmitter and a receiver disposed on the opposite end portions of said handle, said hand set handle being adapted to rest in the notches of said supports in said base, plunger switches slidably operating vertically in the bottoms of said cradle notches, springs in said base normally holding said plunger switches yieldably in raised position; apparatus for magnetically holding said hand set in said cradle including an electro magnet disposed in the handle of said hand set with its pole ends separated longitudinally along said handle, extending outward from the under face of said handle when the hand set is resting in said cradle, an armature magnetically cooperative with said electro magnet pole piece-s disposed on the top of said base between said notched supports, an electric circuit leading from a source of power to a conductor in one of said plungers, thence through button contacts to the winding of the electro magnet in said hand set thence through button contacts to the conductor in the second plunger switch and thence to a release switch on said base and thence back to the source of power, a signal electric lamp on said base included in a circuit so that it will be energized when the hand set is removed from said base, said circuit including a lead wire from said source of power contacts on at least one of said plunger switches arranged to open when the hand set is in place in said cradle and to close when said hand set is removed from said cradle, thence to said signal lamp and back to said source of power.

5. The device described in claim 4 wherein the source of power includes a step down transformer having its primary connected to a volt alternating current power line and its secondary winding has a voltage of approximately 24 volts, and said secondary winding is in circuit with arectifier.

6. The device described in claim 4 wherein the magnet release switch has a vertically extending blade, springs normally holding the blade in raised position, and a switch operated by said blade having its contacts closed when in raised position.

References Cited in the file of this patent UNITED STATES PATENTS m... we- 

